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c( M. PAxIoN. GYROSCOPIC DEVICE AND METHOD.

APPLICATION FILED` OCT. 29,l .1920.

|- FARALLEL W/rH EARTH Axis -r @nvm/Lito@ verri/CA.;

c.. M.V PAXwN, vaoscovlcuvlce Anp Mmmm.

*MPL'ICATlQN FILED OCT. 29, 1920. l

Patented May 31, 1921.

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im :ARM Axis NE PARALLEL WITH BARTH AXIS FIXED SlERAL TIME LINE HTH L l Wes r X ens r aumento/a ('[yford M. Parioli @51m ww fg f5 Cf M. PAXTON.

GYROSCOPIC DEVICE AND METHOD.

APPLICATION FILED'OCT. 29. |920.`

c. M. PAxTo-N. GYROSCDPIC DEVICE AND METHOD.

APPUCATIQN F'iLED OCT. 29, 1920.

1 380,3-35, Patented May 31,1921.

Llllllllllniilm@ im N C. M. PAXTON.

GYROSCOPIC DEVICE AND METHOD.

APPLacArloN FILED oc. 29, 1920.

1,880,335. Patented May 31111921.

s SHEETS-SHEET? 5.

c. M. PAxmN.

GYRDSCOPIC DEVICE AND METHOD APPLICATION FILED DCT. 29, 1920. 1,380,335. Patented May 31, 1921.

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CLIFFORD M z axfrort` or i3nOoKLYN, NEW YORK. '-AssIeNOn r'ro rAxTON eynoseorn commen-Troma CORPORATION OF'NEW YORK, i

eyz'aoso'orrc: DEVICE 'AND METHOD.

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'af Illl oolrly'n? in theycounty Oi4 Kings and f' a ai yI lesi'v 3 l'orlr diere inrented certain nil nsefiilzaprorenients in Gyms-(copie Deiies and lv'elghoglsr, Gase-FJ Of. ti?hich tlielifollowingis agapeoil cation.' g fg' r y. zpresentlinxentlm relates niorepar- 1.0 tiularly to 4gyroacopie devie'esfof thetyl'ge adapted to maintain, Or 'indicate a fixed. di-

rec-tien inspace fluringrotation of the earth. 1n rn'y prior Vapplication,4 Serial'- No, 351,236g filed Januarv '13, .1920, rI hare described among other things two diierent classes `of units having this' Object in View. One of them is thelpara1lel gyroscope so cfalled lbecause it is so' constructed and Operated that the rotary movement of the eartlr' about its axis is `utilized to.4 cause the spinning'axis ofthe gyroseope to maintain faV-poition parallel wit'h'the axis of the V'lliv.sit.. maintains a fixed direction ft-hat of the celestial poles, 4therebgr constituting a compass indicating north and at @the sametime givinga, direct' indication latitiifleOf'th'e place. As described in" said a' pl icatfmifn this4 unit comprises a cii'lpass" Orliolding the Spinnin i 4axis of the"'-arallel gyroin the north ancv s'OuthOr rri'eitidian planfehwhile the parallel gyro Operates to maintain parallelism in said plane. '1n' otherapplications, Serial BT01361257, filati l'4`elirriary 25', i920-, Serial XO. 416.409. 'filed' October l2, 1920, and lSerial XO. 4'zl,G-., tiled November 26'.; 19:20, I have shown and desorilied singlegyro units in 'irhiqh the gyroscopic reactions of a single Erotor" lare ntilized so as to make it seek and maintain both 'the meridian 'plane' and also the position of parallelism in said plane. ,f1-Said application, Serial No. 1351.236, filed January 13, lSlElL'clisclOSes how such parnl lel-gyros'may be employed in combination with another fixed-direction gyro unit which I have called the meridian gym. Mtr 4present invention as also Serial No; 356,045, filed February il. 1920. relates fto themeridian gyro,.so called because it'is adapted direction shown by t e parallel gyro. "lllieplanfe including `'tli'ese, ftwo fixed direcent of longitude indication,v

to maintain or7 indiretta 'a igtediilirection atA an ang-le. preferably' a ri' ht 'angle to the' Speelman-cia of lzeterlsratent.-v Ptenfed-:May 315,192.1. i 'apiaialiba'alci Opmeer 29,4 i920. i y i i Serial .Nol 420,537.2. tions fixed celestial meridian Or longitndeplaiie for the earth through whichlalhme'rid-ian Or long1tude planes of the eartliiiust rotate these two directions` any loaLb-Q'lJ-Or change:

".jadii fe so indicatechconstitrites in vonce 1n twentiufoul; 'hours` .-Hence' with for indication by the meridiangyrornay: theV meridian plane of any )lace On thelearth ,.at `angv l1Onr.Of the da Y. *,Ortggeneral purposes the pOs1t1On yof t emeigdianplane -at Greenwichat noon vislpreferable,altilicm h for specialpurposes the noonposition offtiem meridian plane of the place Where thel ini'"` strnment located, ma* be .areferable Such a meridian'gyro can lieii'seciy formally purposes, but the primary lipose 'which I had in mindis use in comlll' u Ongitude of #thelplace wherej the :nstrrrmeint the, parallel gyro.

in'ation with a parallel. gyroas a :means lforg1ndieatrrrg:the

The availability of' rhieifialiamgym such preferred `purpose-\depend,s .np th fact that it constitutes afeloekdilf ,indicating sidereal time.i Sli'clr 'ag sideral clock has important uses entifrely independsolar day, representing one .complete rayo@ lut-ion of the earth with respecttoltlie'sun.' and hence takes into account the; changept angle of the 'earth with grespectto -t-hew'snn resulting from the earthsorbital Emotion around the sun. 1 Thus'the solar-dayyinvolresiL a rotation of an aierage of VIiearli4v 361?" as regards space, but: the/'excess over the- 3600 varies with the position of the earth'in its Orbit. The other kind of day is'the sidereal day representing one revolution of the eartlr with reference tO-a fixed point in space. A'srotation Of the earth is uniform 1 it lfollows that the sidereal days are all of equal length and the length is the same for'allfpoin'tsf On the earths surface. This, asimeasnrecbyq an'orclinary clock time, is .approximately 23 hours, 56 minutesand 4.1seeonds Obviously it is sidereal timethat will be Vning axis 1n the plane of spin of the earth, which is of course at right angles to the axis of the earth.A The spinningaxis of such gyro would appear to rotate end over end, once in .each sldere'al day, the real motion of course being the rotation of the mounting and of theobserver on the rotating earth, with respect to the gyro maintaining its fixed direction in space. The sidereal time may be read simply by observing the angle of the apparent rotary movement of the gyro spinning axis with reference to a fixed point on its' mounting. i

Such frictionless gyro is impossible, -however, and friction in the pivotal mountings operates tol apply a slight but continuous torque of the rotating earth in the plane of rotation of the earth which is east. Such a torque, as explained in my parallel gyro application referred to above, tends to cause precession of the spinning axis toward parallel with the earths axis. Hence a gyro even if properly set in a plane at right an- -gles to the plane of the earths axis and in a direction corresponding to a fixed meridian Vplane would immediately begin to show yield in the direction of the rotation of the earth and precess out of the planelof spin or other plane at right angles of the eart with the earths axis.

My present invention includes means for automatically preventing and .compensating for such factors of error and inoperativeness. The principles of m invention and. the novelty of my metho s and means Afor obviating the effects of rotation of the earth and overcoming the pole-seeking tendency of the gyro will be better understood from the following reference to well. known` laws of gyroscopic action'.

A high speed rotor develops the mechanical reactions and the peculiar resultant movements characteristic of the. gyroscope only when mounted so as'to be free for angular movement out of the lane of its spin, and when subjected to a orce or torque which will actually cause such angular movement. This an llar torque is usually applied through t e spinning axis which is of course perpendicular to the plane of the spin.

It is a law of the gyrosoope that the movement or dip in the direction of the displacing force will be small, but such movement or dip compounded with the power of momentum of the high speed rotor will cause a resultant movement of the spinningv axis at approximately right angles to the drect m. of the primary displacing effort.

'luis resultant motion is called precession and is peculiar to gyroscopes.

ance on the precessional axis, there will be y and the movementwi 1 be wholly yie 'sion to the right if 4 the rotor is spinning l sd clockwise, or to the leftif spinning counterclockwise.

Furthermore, if precession, isy opposed, as by friction inthe pirotal axisabout which the precessional movement must develop, the direction of the precession will be 'correspondingly less thana right angle to primary displacement torque. That is to say. there will be a porportional' yield or loss of position in the direction of the primary displacement torque. In the special case, where the friction or other opposition to 'precession is prohibitive as where the torque 1s so small or so slowly or so rigidly applied that it cannot overcome the initial starting' resistno precession at all; no gyro'scopic opposition to angular movement will befdeveloped: the displacement tor ne will be unopposed; ding in the direction of the torque. y

The precessional movements and ie'orts are purely mechanical resultants dependent upon. inertia and rotary momentum. This is important, since a gyro spinning axis ends tomaint-ain iixed direction airspace; and in so doing may appeal' to haveimportant andular movements when considered A`with `re erence to the surface of Athe rotatingjearth; only which it is located, and [vice vers" ,fif gyro axis having fixed direction on'v'thepearths'110 surface may have and `usually will'lfhaage imf portant angular movements in spare. l: Q` v In this and certain other connet'onsfthe" axis of the earth may be reckoned-astx'ed direction in space,` substantially unch .311`5 by the earths orbital motion aroundtlj slmtjjf The slight shiftrepresented by'the qgeees sion of the equinoxes is too slow .to 4produce appreciable effects and is therefore --inegligible. y 120 Tith the above principles as a basis my gyroscopic sidereal clock and its possible uses as a clock when located in a fixed position on the earth; or as a longitude indicator when moved about over the surface of 125 the earth. may be explained as follows The gyro has its spinning asis mounted for free end-over-end rntivtlth ih, the plane of spin of the earth.4 that is, iii the latitude y plane 0f 'the place. At the equator this 180 Y stance; iin" latitu de? A309 .D lf'th! the horizontal "Ap-lane' bf thejplace'fi'si at an? `angle 615.309 i ==to 'the earths axis; i Hence, the plane of 'earth spin4 ``Wlll 'he one which includes fan r i east :and 'west horizontalline, and av linle at 'right-"anglesthereto slanti'n' y upward but inclinedffsouthat ananglero ...Sfromthef vertical'of. the place.. a In latitude. 3091, south the same thing; isitue,jexcept= thatthe in.-

clinaltion awayfrom the;vertical of the place,

is'jtowfardgfthe north: insteadotowartl thel =^=sout=h: F'1 `hese-aresimple geometricalrelafr4 tlons easlly observable-by'slicing -ancrange at rigilitranglestoiits' core, the skin ofithe f-orange :representing the horizontal ofithe `'plate@the core the-axis of,l rotation andthe out surface the .plane-ofspin loftheearth. In orderftoi penmitthe end ,overa end rotaftion of .thespinning axis in theplane of the 4 earthsspln, there must -be a pivotal'mountu v 4 terminedi distance in eitherl dlrection.A l

f -ingfa-ii'ordingap'inotalf axis inthe'northand n Isouth or meridian plane, iparallebwith the 3U avearthfs axis." These; n'orth'vand south `pivots iniayube@called the parallelpivotsi and their vfaxis-thedparallel aXis..-g1l. .J j

/, VInyforrezrvthattlie gyro may-develop' its peculiar-*tendency tomaintain fixed direction of its Spinnin exis, Asai'dspinni I-,-,1':xti.ust b'e mountedor freedomfto ,-preilcess in inthe direction of themeridia-n planeiwhich is wtf-rightangles tot-he plane of spin of the l s' ear'thtg EHence, l:the-north-and-.south parv u 4.0f5allel? pivots oarry a ring supporting other v Y pivots havin (their axi'sin theplane of rotation-fofisai' parallel pivots,-J vhich' is also "--t'h'e plane otsp-in ot the earth. 4Hence these second .-pivfots rotate 'end-,over-end with the i rgiyro' spinning axis carriedjthereby, but per-y .V E .mittmg' the.. latterthe required freedom for' ffipreoession,,infthenorth `and `.south planes. e These end-overend mounting'pivots sh'ouldbe as frictionless possible so as to a'ord 50.'the least'possible resistance to prece'ssion in reponseto the earth torque applied in the .plane of the .earths spin, through friction f in the parallel pivots.V p vThe gyro, gyrov casing,

and; pivot rings constituting the universal mounting' therefor., ilrel :ll careull)Y balanced with' respect to allth'reeo-f the 1'axes l of possible movements'sothaty thefgj'ro is in neutral equilibrium 'u'ith respect to gravitvx The parallel piiot liteiiiurs hareapprei The princi )le seems clear nenough. but may "he arit-ilmetically explained as folciable friction. 'so' ",fhat'tliiei"rotating earth applies considerable fractional torque tending' tov rotate thef-gyroaxis' in 'the direction"I of earth spin. In' ord-i'ito permit this to -allel pivots, and 4as compared :with the,

axis,

and thel pivotsl .take effect "te pmiessioe, tdt-(SQ minimum .yield- Ein thef direction ofi Athe torque, which is ealstfandgin ordei-"tcrauto;4 miltically restonge northfonsouth loss Aof' position jdue vlo precession,- employ; "a 2,0

- device forI applyiiig a continuous succession fof torques, on the' 'spinning .axisv Ein' .the plane @foi fthe earthsr silien't torque -isl compared with the torque'iofthe earthxi tion. Theialternlatiu' `req '-.made relatively.. Urea s 75 is applied through friction aroundthe ti 'nalfresistane .to precesfion aroundf-tlie endurer-end pivots. This continuously operating alternating torque is ofsuili'cient '30 power ,to cause4 .relativelyY VWide preoessional 4approximately in: the meridian plaine, and approximately.` equal distances across angl-,on

reach side ofy the planeof 'spin'of 4t e earth.l 'g5 Asa Simple-:wey of m'king't @Presles InV the initial construction of.thefin'stfru-l v ment|, the reilient means for,applying,the torque' in one direction is madea's nearly as ossible identical in construction 1Wlth tha which appliesthetorque .intheother directiom'so that initially, 'and 'except for -V Ylsubsequentfad]ustments; lthe'toi-rfuesfin Op ma -posite directions though'entilrely indepe'n-dlent, will be the-same iI1'"p ')WeA and frate of application. One of the torqnes will work in the same direction with the earth torque. "however,` and 'the other' torque will lWork.' in" opposition to the earthgtorquc. Hence.' the 'primarily equal Vtorques'wo'uld begraduaflly increasing in one' direction anddecreasingr inrthe other direction." AccordingA to my invention Vth-is ma;T he corrected by adjust-frio ing .the tension of thetorquempplyingj springsuutil the` precesson in opposite directions are accomplished in equal times. Now we have equal torques producrigrab solutelxv equaltirne.y equal-distanr'e- 'precession. but the torque in the oneTli-rection represents the alternating torque plus the 'one-direction earth torque. Whilethe torque in the other direction represents ,the alteruatingl'ftorqu'e. minus theearth torque. An important feature of my invention is `that 'ull of the Variables can be taken careofihy trial 'regulations of .the adjusting means.

until the instrument keeps-approximately correct sidegeal t1me.vn'ltl|lnA the limits rev-"- quired for otheraccurate clironometers lowstl Let a' equal the value to which' the earth 22T* .in tlie direction opposing earth torque falls 't0 149.1.

YVe may now adjust the resilient torque-applying means until the one o ier- 'ating with earth torque applies an initial torque of 149.1; Such torqlue beginningat 149.1' will be gradually bui t np by the in- ,creasingr earth torque to a tinal value of 150.1I

while the torque in the opposite direction beginning at 1541:@ will t'all to a tiiial value of 149.2'. It is the a: difference in the initial torqiies that is important` and .so fat' as conceriis this. the actual values might be 129.r as against 130.1d or 104m as against 165.1.

In either case the alternatinglr toiqiies actually exerted will be ot" equal average value and equal total value as well astor equal times and through equal distances. Moreover the time rate ot' change will be identical for the increasin; r values in one direction as for the decreasing.r values in the other direction. The important point is that the one-direction earth torque has been` nome-na described in niy application. Serial No. 496.60Hj. tiled November 2G, 1920, in so far as these phenomena may be developed,

will also be equal` symmetricaland opposite,4

both equal to .r the yield iii the direction of Y the torque would be equal to the precession at right angles to the torque. It is toiinprov'e this situation that the reciprocating torque is; made very great as compared with .the resistance opposing! the precession. Also. aspu'inted out in my said application, Serial No. Jft'nttNLl. tiled oveinber 26, 1920, the powerful alternatingr torque of proper frequency and power should be applied through a properly designed resilient meinbei', such as will operate to cause instantaneons clean-cut dip followed by restoration 'ot' dip permitted by the resilience otsaid member. and a resultant precessioii at an angle of almost exactly 90" to the torque.

Then the .r earthtorque being: superposed on and submerged in the equal (15th) alternatingir torques all ,the friction and inertia oppositions to precession are taken ca're of and the earth torque precession expends itself as part of existing precession in the,

fixed direction meridian plane which itz-is the purpose of the instrument to maintain. Moreover any possible yield in the direction ot' the torque disappears as being part of the yield which is equal and opposite for two directions ot' the alternating preeessional oscillations: as also any possible curl at the-ends of the precessioiial movements.

The alternating torques on the pivots causing precessioii in the fixed meridian plane and the amount of precessioii allowed Ain either direction before the cut-outs will operate to reverse the torque and reverse the a precessional movement of 3 and 6 or more degrees across and on either side of the eartlis spinning plane can do no harm since all such movement is approximately within a fixed plane and cannot show up as a substantial disturbance so far as concerns correct indication of the direction of the fixed meridian plane. The duration of the torque in either direction may also be varied within considerable limits, but three to sixV complete oscillations perminute may be found iractically convenient.

Applying the torque through a resilient medium is of great advantage since it permits sudden application of a maximum effort while decreasing the yield or loss of position of the spinninfr axis in the direction of the torque. rllliat is to say, the dip in the direction of the torque is followed by gyroscopic recovery, or return movement against the resilience of the torque, so that the precessional resultant is more ne' rly at right angles to the tor ue, and theiefore more exactly in the meridian plane which it is the purpose of the instruynientto indicate.` The same torque rigidly and unyieldingly applied would absolutely prevent any lLfyroscopic recovery of dip. iloreover, according to my investigations, the `torque when slowly applied through a rigid member that cannot follow up the dip and does not permit recovery thereof, results in relatively larve a ield in the diiection of tlie'torque and re atively small precession at right angles to .the plane of the tor ue.

here remain for consideration onl the instants between reversal of torque. ith the apparatus shown herein the gyro is free and subjected directly to earth torque during` these instants. imd collectively, in the course of time, this might show an accumur spinning lane of the earth. A means for lated yield in the direction of the earths rotation. To compensate for this, the movement against the earth torque should be 'slightly lengthened as to time so that the torque will be correspondingly less than that acting with the earth torque.

.When my meridian gyro is used on a ship, submarine or other transport, as a means for finding longitude, it is necessary to have `ordinary mechanical chronometers keeping sidereal time in any usual ivay, as by carefully regulated spring and escapement few feet during the engagement of the mechanlsm. Preferably the dial or indicatorwill be graduated as a 360 circle, but if graduated in hours, translation into degrees 1s a Ysimple matter. The dii'erence between the time as shown by the mechanical chronometers, as comparedwith the apparent time shown by the gyro chronometer, will 4be the number of degrees of longitude that the ship has been moved east or west.

'A rough appreciation of this may be had from a consideration of the gyro chronometer carried entirely around the earth at the equator. If it were carried east in the same direction with rotation of the earth it would apparently gain a whole day in the course of the journey, and if carried West it would ,lose a Whole day. This is because the mountin index being kept right side up during t e journey, is necessarily rotated one complete revolution around the parallel pivot mounting of the fixed direction gyro, While thel mechanical clock so carried around the World would gain or lose nothing by reason of the transportation. So a journey one degree or a fraction of a deree east or west, will show a degree or a raction of a degree gain or loss by the gyro chronometer as compared with the mechanical chronometer; and conversely observation that such gain or loss has been made viil prove that such distance has been trave e l Theoretically there is froom for possible error due to movement of the instrument on the earth in directions having an east or west component which might require corrections for speed if Vthe error were perceptible over a period of days, but such error would be so slight as to be negligible for the following reasons. In applying the mechanical torque we are multiplying the earth torque `(as it affects a gyro) many, many times and the movement of a ship over a clutches each time` would not vary the precessional path sufliciently to lead to error d-aning axis can turn end over Aend in the accomplis ling this on a ship or other unstable platform, is fully disclosed in n1 prior 'applications above referred to. Iii may be stated, however, that such means includes a parallel gyro on a stabilized base adapted to maintain itself parallel with the axis of the earth. The mounting of this parallel gyro is provided with commutators in operative relation to its compass index and its latltude lndex respectively.

`These close successive circuits Whenever which is stabilized gyroscopically or otherwise and this may be the same base that is used to stabilize the parallel gyro.

Repeaters may be employed to repeat the motions of the gyro-or its apparent motions, to other mechanisms, such as a differential commutator as described in my original application, Serial No. 351,236, tiled January 13, 1920, or any other devlcc` or mechanism, including astronomical instruments.

In addition to the above described basic features of novelty and invention, my meridian gyro includes certain important improvements in the details of construction and operation, as for instance, the electromagnets as means for applying the alternating torque in the direction of earth torque.' They are ofspecial advantage as affording means for instantly applying, continuing and removing torque of a desired predetermined amount; also for applying said torque with a resilient follow-up and return, such as is required to produce approximately ideal dip, complete recovery of dip and precession at right angles to the torque; also as a means for instantly winding up the torque spring to the desired predetermined tension; also for easily regulating said tension by varying the stroke of the magnet armature. By this means of operating through properly selected torque springs the instrument can be regulated for regulated, the battery or other source of energy for the electro-magnets may vary in strength through a considerable range provided only that it remains sufficient to afford a full, quick stroke of the armature.

' It Will be noted that While the functioning of the alternating torques applied -as yabove describedwresembles the rocking device described in my prior ap ilication. l\`erial No. 426.60%. tiled Novem er 26. i920. in that it magnilies the effects of earth torque and causes efficiently executed pri-,cession in response thereto, causing such precession to be nearly at right angles to the torque and with minimum yield or lossof position in the direction of the torque. nevertheless. the functioning in the present case is quite .different in detail. Here the one-direction earth torque is superposed on unequal alternating torques o .such values that the effective net alternating turques are equal.` similar, and opposite, for the purpose and with the result ot' completely canceling the effect of earth torque. \'hereas in the prior application the rocking device is carefully designed to apply torques which are initially equal'so that the superposed earth torque will make them unequal t'or the purpose and with the result of making the earth torque as effective as possible in causing rapid precession away from the plane ot' spin of the earth and toward parallel` with the axis of the earth. Also in the prior case the rocking device operates many times during a single period oi continuous application of increasing earth torque. In this latter aspect it will be noted that a rocking device could be actually added to my .present device to operate a number of times during each precessional movementfeven though inpractice such rocking device might not be necessary or desirable. Also the electro-magnet as a means tor winding up a spring to apply a predetermined torque` could well be used in place of the crank and link rocking device of said prior parallel gyro a plication; or the magnets could be used irectly as the resilience element4 of the torque applying means. the armature gap. retracting spring and strength ot magnetizing current being adjustable to vary the strengths of the resilient magnetic pull.

4The above and other features of my invention may be more fully understood from the following description in connection with the accompanying drawings. in which Figure 1 is a top plan View of the instrument. the parts in this and other figures being shown in the positions they would have at noon at the equator. and the several geographical relations and indications being indicated by legends;

Fig. 2 is an elevation of the same apparatus looking north;

y Fig. 3 is a partial section and side elevation on the line 3-3, Fig. 1;

Fig. 4 is a detail on the line 4 4. Fig. 2:

Fic'. 5 is a detail on the line -i. Fig. 1:

Fig. 6 a detail section on the line (Sw-(.

i is a detail section on the lintl T.

Fig. S is a detail section on the line 8--8, Fig.

Fig. Si is 4a plan View of the electro-magY netic switch tor cutting out the circuit ot one torque magnet and cutting in the circuit of the other;

Fig. 1U is a side elevation of the same;

Fig. il is a` diagram ot' the circuits with the parts conventionally indicated;

Fig. 12 is a diagram indicating geographical relations with respect to the earth as view endwise with respect to the axis; and

Fig. 13 is a similar diagram of the earth viewed edgewise of the equatorial plane.

In these drawings the primary support of the apparatus, functionally considered is the rigid frame 1 which is ,maintained in a. plane. oi which the east and west lines are horizontal andthe north and south lines, parallel with the axis of the earth. If-the instrument is used in a fixed location, as for astronomical purposes'. the frame 1 may be fixed on an earth foundation. It Inay,h0w ever. be supported as shown since the` automatic means described below as necessary for use on ships. may be kept inoperative, thus holding the'parts in lixed position.

Then the device is to be used on ship board. however. the frame 1 is provided with pivots 2, the axis of which is horizontal. east and west. These pivots are supported in bearings 3 in the fork -l having a vertical pivot 9. supported on base 16j". in the same plane as horizontal pivots Q. The primary support being unstable and capable of horizontal turning movements. the frame 1 is kept with its pivots 2 east and west by rotation of the vertical pivot 9 and with its north and south lines parallel withl the axis of the earth by rotation about the horizontal pivots 2. The latter movement is hy means ol segmental rack 5 operated by pinion driven by motor 7 controlled through circuits 8 connected with the latitude-indicating elements of a parallel gvroscope such as Shown in my prior applications. above referred to. The east and west is preserved by gear 12 driven by pinion 13 rotated by motor 14. controlled through circuits 15` by co mutator circuits connected with the north indicating elements of the parallel gyro. Repeating circuits for this purpose may he those well known in the. art or may be the special repeater circuits de scribed in my prior application.

The frame 1 supports in the north and south or meridian plane. the pivots 17 of gimbal ring 16. pivots. Ring 1G supports pivots 20 with 1 their axis perpemlicular to the axisof said pivots 1T and hence adapted to rotate end over end in the plane of spin of the earth. These pivots permit the to andfro processional movements in the fixed plane, and may be called the preecssional pivots" These are the parallel Said precessional pivots 2O are in the form of studs on the gyro motor case 21, the spinning axis .r of which is vertical in the position shown, which is that of noon at the equator. But it is free to rotate end over end in the plane of spin of the earth about pivots 17. The rotor within the casing is of any known or desired construction. comprising the usual gyro wheel. and means for driving it. the latter being preterably a three-phase motor the field of which is stationary and the armature of which is located on the rotor.

The parallel pivots 1T are the ones around which the frame l must rotate while the spinning axis4 maintains its fixed-direction meridian plane and it is `the friction in these pivots which tends to apply the earth torque which would canse yield in the east and west plane and precession in the north and south plane` the former constituting erroneous indication and the latter operating eventuallyv to bring the gyro parallel with the earths axis where it could not function as a meridian gvro. AHence, it is around the pivot 17 that apply the alternating torque. Ther means for applying it, see Figs. l. G and S. include two similar but oppositely acting assemblies at opposite ends of the parallel or torque pivots 17. Each comprises a clutch member 30 longitudinally fixed but rotatable on vshaft 17 "and a clutch member 3l longitudinally movable on stud shaft 17` which latter is held fixed in bracket 1S. on frame l, by a set screw 17h.

The clutch member 30 applies torque to shaft 17 through spring 51 surrounding hub sleeve secured at 53 to said clutch 30 and at 54 to a collar 55 secured to shaft. 17 by set screw 56.

The movable clutch 3l is operated by clutch magnets 32 attracting armature 33 which is slidable on the hub of member-31 but which operates on 31 through a relatively strong spring 3l in opposition to another weaker spring B-l". Hence, on compression spring 3ft acis first and on expansion 34 acts first.

The movable clutch member carries parallel guide screws 35 on which the armature 33 is slidable. The arrangement is such that when the magnet 32 is energized. lhe spring 3l being at tii'starnyieltlilig the armature 83 forces clutch member El into firm engagement with member 3G. then spring 34 yielding. further movement closesy contacts 236-37 of the torque-applying magnet. ll'hen magnet 32 is deincrgized the stronger spring 34 first forces armature 33 rearward: thus disengaging contacts 36, 3T; then further expansion ot` spring 34 being prevented by the heads of guides 35. the weaker spring 34 will expand disengaging clutch 3l. Thus the torque applying magnet 'annot possibly start to apply torque until the clutch is locked. and the torque is released before the clutch is disengaged.

Contacts Sti-3T control the circuit tl 'it energizes torque magnet 3H. the armature 3H ot which is rigidly secured to clutch member 3l. The initial position of armature 'ltl with respect to stop 4U en the magnet pole is regulatedby set vcrew -ll secured by lock nut l2 on support lil. which is also the support for the electro-magnet and which is in turn supported by bracket 1S on frame l. The length of the A-troltc ot' armature Btl as determined by .screw 41, will fix the amount of torque applied to torque spring 5l whcn.thc torque magnet 3H is energized. The armature 39 is restored to the tracted position. in contact with screw l, by spring 44 connected to the armature 39. extending freely through passage l5 in support 43. and adapted to be adiustably ten sioned by set screw 4G. secured by lock nut 4.7.

The set screw l1 for adjrsting the initial gap between torque armature Il.) and the pole of torque magnets 1% regulates the respective torques that will be applied to `shaft 17 through spring 5l in one direction. and the cori.es}mnding spring operating on said shaft in the opposite direction. The magnets 38 and all other parts for producing torque in the opposite direction to 3S are located on the other pivot 17. the corrcspo'uling parts being indicated by the same numerals with a prime mark added. The longei the armature gap, the more the torque irings will be wound up. when the electro-magnet 38 or 3S attracts the coi-resp(aiding.;` armature Il?) or 39. Preferably the electroni iagncts are strong enough to throw the armature. the full distance. with an instantaneous snap when the circuit is closed through contacts. 3G. 37.

'l`he apparent end over end rotation of the spinning axis in the cast and west spinning plane of the earth. which is really ro. tation of frame l around the parallel. torque pivot 1T may bc accurately indicated and read by means of an index 23 secured on frame l in operative relation to a dial Q2 secured to ring 1G by projections 23 and screws Qi. y

The means for cutting out one torque and applyi`ng the other at the end of" the respective precessional movements include a contact maker on the precessional axis 2H in combination with an ordinary relay on the. Jrame ot the machine. The contact maker comprises an arm G0 having end forks 61 in operative relation to fixed contact` screws (32. (i2 held by. lock nuts G3. 63 on brackets G4, G4, on ring 16. The contact maker G0 sii is rigidllv secured to shaft 20 by set screw 2W. lts shank is preferably ot` somewhat Ilexihle spring steel so as to permit ot' slight vield upon making contact with either Yof the Astationauv screws (l2. (3:2. at the end of a prcccssional movement. This permits the g vro to terminate its precessional movement naturally. without material counter pressure such as would he developed if the contact were rigidly made. The screws62 are adjusted fm' the purpose of predetermining the extent or the desired precessiohal movement and for causing them to extend precisely equal distances across and on both sides of the plane of spin ot' the' earth.

The circuits for accomplishing the above purpose are diagrammatically indicated in' "ig. ll. The clutch-operating and torqueapplying circuit is from any suitable source ot' power through wire-(1, collector ring al on vertical pivot a. wires a2. a?, a4 to one of the electro-niagnets T0 of the relay; thence through Wire ring (Le on the parallel or torque pivot. wire HT. stationary contact (l2.

` and preccssional contact-maker 60 to ground through the frame. ot' the machine. Thisl holds relay switch Tl in Contact with 73, closing circuit through Wires b1. b2. to clutch magnet 32 thence through wire r'* to ground. The `clutch magnet having operated the branch circuit is closed from b1; through c, contacts 3T. 3G. Wire c1 to torque magnet 38 thenA wire c: to ground.

This situation continues while precessional movement is moving the precessional contact fork 60. (ll from one position shown, into contact with the other stationary contac 6'2. This closes circuit through the other coil T0 of the relay magnet. wire om, collector ring am. Wire a. through ('12 and (loto ground. This throws relay switch Tl into contact with 72 thus closing circuit through Wire b, clutch magnet 32' and Wire L13 to ground. The clutch havingr ope `ated, contacts 36', 37 will be closed therehy closing a branch circuit through wire el, contacts 36', 37', wire c, torque Vmagnet 38 and Wire cl2 to the ground. i

The three-phase current for spinning the gyro. is brought through Wires 77, g, r collector rings p', g', r', Wires p2, gf, r2, rings p3 qs. r3, wires p4, g4, r4, to termmal r. 75. r". on the `gyro casing, and thence to the interior motor in the usual Way. Ring connections upon the precessional pivot Q0 are not necessary because the precessions are mercl rocl 'ing movements Within the limits permitted by contacts 62, 62.

When the device is used as a clock in a fixed location so that the frame -l can be readilv set on a fixed earth foundation the shafti! and ring connections thereon, may be eliminated.

lWhen the device is used with repeater c ircuits for maintaining frame, 1 parallel with the earth the circuits for vertical repeater motor 14 may he through Wires d1, e, f, o, Without the need of ring connections.

epeater motor 7. however. for maintaining frame 1 parallel. with earths axis will require ring contacts on the vertical axis 9. As shown these circuits comprise a branch from r1.2 through al to repeater motor 7, and thence through Wires e, f, g to rings e, f1, g1, then through e2. f2, g2, to the commutator segments on the latitude indicating elements of the parallel gf ro.

In operation the device may be constructed, assembled substantially as shown in the drawings, the frame l being parallel with the earths axis and the gyro spinning with .its spinning axis free for end over end r0- tation in the plane of spin of the earth. The screws (3Q on the parallel frame l will be adjusted to permit equal precessional movements on both sides of the spinning plane of the earth. The arc of the precessional movements will pret'erably be considerable so as to reduce percentage of the error introduced by any inaccuracy of this adjustment. For instance, if the precessional movement should be through an angle of scconds on one side lof the plane of earth spin and 10 seconds on the other, the error would be a .large percentage, Whereas it the procession were 5-59-55 onel wa v as against 6-0-10f theother way, thc percentage error would be Very small. Errors introduced by such asymmetry of the procession are likely to be small in any event because earth torque on a gyro axis in the spinning plane of the earth has only slight change of value for small angles on either side of the spinning plane of the` earth. will be conjoined with regulation -oi' the stroke ot' torque armatures 39, 39y which determine the amount of wind-up that will be applied to the torque springs 51, 5l',

as soon as the clutches are firmly engaged.

These tivo adjustments particularly the stroke of the torque armature will take care oi a multiplicity of inaccuracies which it might be impractical or impossible to discover and measure, all of them being propcrly taken care of and compensated for by trial adjustments until the gyro keeps substantially correct sidercal time throughout a sidcreal day. The geometrical relations of the device with respect to the earth are indit-ated by legends on theI diagrammatic views, Figs. l2 and'13. Fig. l2, when the axis of the earth is viewed end-on, shows how the gyro spinningr axis maintains its fixed direction in Space during rotation of the earth. Assuming position A to be noon@` at the equator, the spinning axis is vertical, an inclination ot' 45 as at B will show that three hours has elapsed; the horizontal position of C shows that six hours has elapsed The regulation of the contacts 62 105 5 of the equator being opposite.

5 whereas it is 5 the ship is stationary.

and the downward inclination at D shows that nine hours has elapsed. The diagram also indicates hoiv these apparent changes of inclinations are iii fact movements of the 5 mounting and of the observer with the earth.

the frame 1 maintained parallel ivitli the axis of the earth, appears to have different inclinations for different latitudes, the position at the equator being horizontal and the apparent slant for positions north and south This view also indicates hoiv the frame 1, being maintained parallel with the earth and vvith its east and West lines horizontal, must describe a cylinder successive positions of which are 0 indicated at E, F and G. The fixed direction spinning axis u which remains within limits either side of the plane of spin of the earth, considered from earth vievv point appears to rotate end over end in said plane, really the frame 1 which is being rotated around the fixed-direction spinning axis of the gyro.

The meridian gyro as herein described, when used on ship board to calculate loiigi- 0 tudc, will be of very great practical value even though poorly regulated. For instance, if the yield or loss of position due to earth torque is inefiiciently compensated for or is over compensated for so that the clock 5 shovvs a gain or loss of time during a day or a succession of days, the error can easily be kept track of and alloived for, as this is what navigators are Well accustomed to `doing in the case of their ships chronome- `:01ers When navigating by astronomical observation in the usual ivay. Moreover, if the north and south axes are not exactly parallel with the earths axis so that the endoVer-end apparent movement of the gyros 5 spinning axis slioivs an apparent ivabble across the plane of spin of the earth. the only effect ivill be that the gyro Will show a cyclic gain followed by a compensating loss during each twenty-four period, the in- 0 dication being exactly accurate tivice every twenty-four hours. Moreover. the iiitermediate vvariations can be tabulated and allowed for by comparison with the ordinary ship chronometers, preferably at times When Similarly, error due to having the oscillatoryv .precessions inequal distances on'either side of plane of spin of the earth or eyen wholly on one side of said plane of spin can be tabulated 0 and allowed for.

In a device properly constructed and regulated none of these errors are necessary anf ne above is merely to show how a somewhat disordered .meridian gyro may. be

5 made of 'incalculable value to navigators yvithout the necessity for attempting read- ]ustnieiit or regulation during a voyage.

I claim i 1. The method of enabling a freely mounted gyro to maintain its spinninr axis approximately in a fixed-direction ce estial meridian plane. which method consists iii applying counter-torque to obviate the effects of earth torque. as regards tendency to rotate the gyro axis in the plane of earth spin, and as regards tendency to cause precession at right angles to said plane.

2. In the method specified by claim 1 the further feature of applying, in the opposite direction to the earth torque another torque substantially equivalent to the first torque in total value. average value, duration and time rate of change of values.

3. In the method specified by claim 1, the further feature of permitting the earth torque to cause precession for a definite period; then applying in the opposite di rection, a torque adapted to produce coun.

ter-precession, the time, distance and speed of which are similar to and compensating for those of said procession.

4. In the method specified by claim 1 the further feature of permitting the earth torque to act cumulatively and resiliently for a predetermined period and then for an equal period applying a similarlyresilient, opposite torque having an initial value equal to the final cumulative value of the first applied torque and the earth torque at the end of said first-mentioned period.

5. In the method specified by claim 1 the further feature of applying in the same direction with the earth torque, for a pretermined period` a resilient torque having a predetermined value much greater than that of the earth torque and then for an equal period applying in the opposite direction a similar resilient torque less than said firstmentioned predetermined torque. by an amount equal to the value of the earth torque. for the purpose and with the result of making the net torques equal in value, time and time rate of change.

G. In the method specified by claim 1 thc further feature of applying resilient torques alternately with and against the earth torque adjusted so as to cause equal and opposite precessional movements.

7. In the method specified by claim 6 the further feature of applying the alternating torques during equal times.

8. In the method specified by claim (i the further feature of having the precessional movements extending substantially equal distances on either side of the plane of spin of the earth.

9. In the method specified by claim 6 the further feature of utilizing the pi'ecessional movements to reverse the torque.

10. In the art of operating gyroscopic ing torque of much apparatus, the method of modifying yield in the direction of an applied torque tending to rotate the gyro out of the plane. of its spin and of modifying the preeession against resistance in response to said torque, which method consists in causing said torque to take effect through a resilient medium having an initial predetermined tension.

11. In thev art of operating gyroseopie apparatus, the method of modifying yield in the direction of an applied torque tending to rotate the gyro out of the plane of its spin and of modifying the precession against resistance in response to said torque. which method consists in periodically applying in opposition to said torque, a torque whit` h approximately uniform throughout each period of its application.

12. In the art of operating gyroseopie apparatus. the method of modifying yield in the direction of an applied torque tending to rotate the gyro out. of the plane of its spin and of modifying the procession against resistance in response to said torque. which method consists in periodically applying in the same plane with said torque. an alternatgreater amount for periods sufficient to produce opposite equal disn tance recessione.

13. he method of preventing loss of position in operation of a gyro maintaining a fixed-direction plane, which method consists in applying resilient torque alternately with and against a disturbing torque. said alternating torques being of such amounts as to make the net opposed toi-ques equal.

1l. In the art of operating gyroscopie apparatus in which the gyi'o has pivotal mountings about two axes angularly related so that precession about one axis may be produced by earth. torque applied about the other axis, anda` resilient medium associated with the earth torque pivotal mounting. the method of superposing a predetermined alternating torque and a one direction earth torque. tending to rotate the gyro out of the plane of its spin` which method consists in periodically coupling the earth torque pivotal mountingr to an earth anchorage, through said resilient medium and initially tensing said medium toa predetermined degree, against the earth torque so as to be gradually decreased thereby1 and then With the earths torque, so as to be increase-d thereby.

15. The method of regulating a sidereal eloek gyro operating according to claim i4 n'hif'h method consists 1n adjusting the 1nitial tensions to unequal initial values until the gyro keeps approximately correct sidev real time.

16. In the method specified by claim loj the further feature of adjustin'r the range of the precessions in responaf.` if .fl lie.- Silient torques.

17. In the method specified by claim 16 the further :feature of causing the precessional movements to automatically reverse the resilient torque1 in accordance with the distance of the preressional movement.

18. A freely mounted gyro, means for spinning it and means to maintain its spinning axis approximately in a fixed-direction meridian plane. including means for applying counter-torque to obviate the efforts of earth torque.

19. In the apparatus specified by claim it: the further feature of neans for applying, in the opposite direction to the earth torque another torque ot Ysubstantially equivalent total value. a vel-age value, duration and time rate of change of values.

2d. In the apparatus specified by claim 1S. the further feature of releasahle means for permitting the earth torque to cause preeession for a definite period: and for then applying in the opposite direction. a torque adapted to proflur-e eounter-preeession` the time, distance and speed of whirh are similar to and compensating for those of said preeession.

Qi. In the apparatus specified hy claim 18 the further feature of resiliently operating means through n'hirh the earth torque acts aeeumulatirely for a predetermined period and means for then applying for an equal period a similarly-resilient, opposite torque haring an initial value equal to the final cumulative value of the applied torque at the end of said first-mentioned period.

ln the uliqniratus specified hy elaim 19 the further feature of means for applying in the same direction with the earth torque, for a predetermined period. a resilient torque having a predetermined value much greater than that of the earth torque and than for au equal period applying in the opposite direeiion a similar resilient torque whirl) is less than said first-mentioned predetermined torque. by an amount equal to the value of the earth torque. for the pun pose and with the result of making the not torques equal in value, time and time rate of change.

Q3. In the apparatus specified by claim 18 the further feature of means for applying resilient torque-s alternately with and against the earth torque and means for adjusting said torque so as to cause equal and opposite preeessional movements of the gym.

24. In the apparatus specified by claim 23 'the further feature of means adjusted so as to cause the alternating torques to be applied during equal times.

25. In the apparatus specified by claim Q3 the further feature of adjusting means for causing the 'pref' l`ional movements to ei. 1* ul substantie e. "i the plum of spi: In the :qoparatus spec t earth. ined lay claim Sii@ kes the further feature of means operated by the precessional movements, to reverse the torque.

27. A freely mounted gyro, means for spinning it and means for modifying yield in the direction of an applied torque tending to rotate the Gyro out of the plane of its spin and of modifying the precession against resistance in response to said torque, said means including resiliently acting means having van initial predetermined torque through which said rst torque is applied.

28. A gyro freely mounted to maintain a fixed-direction plane, means for Spinnin it, and means for applying resilient torque azernately with and against a disturbing torque, said alternating torques being of Such amounts as to make the net torques equal.

29. An earth anchorage, a gyro mounting, a resilient medium for coupling said mounting to said anchorage, a gyro freely pivoted in said mounting, means for spinning the gyro' and means for superposing a predetermined alternating torque on the one-direction earth torque which tends to rotate the gyro out of the plane of its spin, said means including a clutch element for periodically coupling the gyro mounting to said earth anchorage, through said resilient medium, and means for initially tensing said medium to a predetermined degree, a ainst the earth torque so as to be gradua ly decreased thereby, and then with the earths torque so as to be increased thereby.

30. A gyro, means for spinning it and a mounting therefor comprising pivotal axes, means for maintainin one approximately parallel with the eart axis and the other perpendicular to said parallel axis, in coinbination with means for applying alternating torques to the parallel axis.

31. A gyro, means for spinning it and a mounting therefor comprising pivotal axes, means for maintaining one approximately parallel with the earth axis and the other perpendicular to said parallel axis, in combination with resilient means for intermitteIitly applying torque about said parallel axis.

32. A gyro, means for -spinning it and a mounting therefor comprising pivotal axes, means for maintainin one approximately parallel with the eart axis, and the other perpendicular to said parallel axis, in combination with resilient means for intermittently applying torque about said parallel axis an( means for instantly tensin said resilient torque to a predetermined egree.

33. A gyro, means for spinning it and a. mounting therefor comprising pivotal axes, means for maintainin one approximately parallel with the eart axis, and the other perpendicular to said arallel axis, in combination with independlently acting resilient means for applying torque .about the paralv lel axis, in opposite directions,

' said parallel axis,

alternately.

34:. A gyro, means for spinning it and a mounting therefor comprising pivotal axes, means for maintaining one approximately parallel lwith the earth` axis, and the other perpendicular to said parallel axis, in combination with independently acting resilient means for applying torque about the parallel axis, in opposite and means on the other pivotal axis operating to cut out one torque-applying means and cut in the other, when recession in either direction has progressed a predetermined distance.

35. A gyro, means for spinning it and a mounting therefor comprising pivotal axes, means for maintaining one approximately parallel with the earth axis, and the other perpendicular to said parallel axis, andy means aifordin an earth anchorage in operative proximity to said axis, in combination with similar independent, oppositely acting assemblies for applying torque to said parallel axis, each assembly comprising a spring, an electro-magnetically operated clutch for coupling said pivotal axis to said earth anchorage through said spring, a second electro-magnet for shifting the anchorage point to tension the spring when said clutch is engaged, and means for operating said torque assemblies alternately.

36. A gyro, means for spinning it and a mounting therefor comprising pivotal' axes, means for maintaining one approximately parallel with the earth axis, and the other perpendicular to said parallel axis. and means affording an earth anchorage in operative proximity to said axes, in combination with similar independent, oppositely acting assemblies for applying torque to each aembly comprising a spring, an electro-magnetically operated clutch for coupling said pivotalaxis to said earth anchorage through said spring. a second electro-magnet for shifting the anchordirections, alternately,

termined elastic torque about said parallel axis and means for predetermining the initial tensioniof said elastic means, including an electro-magnet and armature operating to tense said elastic means more or less according to the extent of relative movementof magnet and armature when the magnet s energized.

-ing an electro-magnet 38. A gyro, means for spinni g it and a mounting therefor comprising "votal axes, means for maintainin one approximately parallel' with the eart axis, and the other perpendicular to said arallel axis, in comiiiation Awith means fgr applying a predetermined elastic torque about said parallel axis" and means for predetermining the initial tension Iof ,said elastic means, includand armature operat-` ing to ten'se said elastic means more or less Aaccording to the extent of relative movement means and cut in the other, when processionin either direction has determined distance.

40. An earth anchorage, a gyro, means for spinning it, means for mounting said gyro in said anchorage and affording two axes of pivotal movement angularly related so that recession about one axis may be produced Ey torque applied about the other axis, in combination with similar independent, oppositely acting assemblies forl applying progressed a pretor ue to one of said pivotalaxes, each assem l comprisin a spring, an electro-ma netica ly operat clutch or coupling said pivotal axis to the earth anchorage throufgh said spring, a second electro-magnet or shifting the anchorage point to tension the spring when said clutch is engaged, and means for operating said torque assemblies alternately.

41, An earth anchorage, a gyro, means `for spinning it, means for mounting said gyro` in said anchorage and afl'ordin two axes of pivotal movement angularly re ated so that procession about one axis may be produced combination with simil positely acting assemblies for app ying torfie to one of said pivotal axes, each assein ly comprising a spring, an electroma neticall operated clutch forv coupling sai pivota -axisto the earth anchorage through said spring, a` second electro-magn et for shifting the anchorage oint to tension the spring when said c utch is eiigaged, and means on the other axis operated b precessional movement to release the c utch and torque spring causing the pre cessional movement and to clutch and tense the other assembly Vto cause procession in the opposite direction.

4 A gyro, means mounting therefor affording two axes of pivotal movement angularly related so vthat recession about one axis may be produced for spinning it, and a Y by torque applied about the other axis, Kiii ai: independent op'- y torque applied about the other axis, in e combination with means for determined elastic torque about one of said pivotal axes and means for predetermining' the initial tension of Vsaid elastic means, 'including an electro-magnet and armature operating to tense said vel less according to the movement of magnet and extent of relative magnet is energized.

A gyro, means for -s inning it, and a mounting therefore affording two axes of pivotal movement singularly related so that Erecession about one axis may be produced y torque appliedV about the other axis, in combination with means for applying a predetermined elastic torque about one of said pivotal axes and means for 4pi'edetermining the initial tension of said elastic means, including an electro-magnet and armature operating to tense said elastic means more or astic means more or armature when-the 'applying a pre# less according to the extent of relative movement of magnet and armature when the magnet is energized and means for adjustably limiting the extent of such relative movement.

Signed at New York city in the 'county of New York and State of New York this 26th day of October A. D. 1920.

CLIFFORD M. PAXTON. 

